Download Production of Daphne X Burkwoodii `Carol

ORNAMENTALS
NORTHWEST
ARCHIVES
March-April
1989
Vol.13, Issue 2
Pages 4-8
R. L. Ticknor, Horticulturist, Oregon
State University
North Willamette Experiment Station,
Aurora, Oregon
PRODUCTION OF DAPHNE X BURKWOODII `CAROL MACKIE'
Attractive variegated foliage, fragrance, and a compact mounded growth habit make Daphne X
burkwoodii `Carol Mackie' a candidate for wider landscape use. It was first noted as a branch
sport in the yard of Mrs. Carol Mackie in Far Hills, New Jersey in 1962. The late Don Smith of
Watnong Nursery, Morris Plains, N.J. propagated the sport and registered the name in 1969.
However, more information on propagation and growing was needed before this plant could be
widely grown by the nursery industry.
Daphne x burkwoodii is the result of a cross by Albert Burkwood in 1931 (2) between the
evergreen D. cneorum and the deciduous D. caucasica. Three plants were raised, but one died.
`Somerset' introduced into the U.S. by Wayside Gardens is the best known form while `Albert
Burkwood' is usually sold as D. x burkwoodii. Based on growth habit (3' tall and 5' wide at 10
years), it is thought that `Carol Mackie' is a sport of `Albert Burkwood'. There is one other plant
which appears to be a D. cneorum x D. caucasica hybrid. It occurred as a chance seedling in the
Morel & Lavenir Nursery in France in 1919 or 1920 and was introduced under the name D.
lavenirri in 1930 (2).
Table 1. Effect of media and fertilization on rooting of
`Carol Mackie' cuttings stuck on October 1, 19841.
Media x Fertilizer
Treatment #
Cuttings;Rooted2 Percent
12/13/84
3/19/85 Total Rooted
#1. Perlite 100% ......................................18
#2. Perlite 80%, Peat 20% .....................
# 3 . Perlite 80%, Peat 20% + Osmocote3 .
#4. Perlite 80%, GCC 4 20% ...................18
#5. Pumice 100% .........................................6
#6. Pumice 80%, Peat 20% ......................10
#7. Pumice 80%, Peat 20% + Osmocote3
#8. Pumice 80%. GCC4 20% ...................... 19
I
.
1..
..19
.12 ....12
. .. 13 . ..13
6
24
8
14
8 . ...18
7 ..........7
2 .. .. 21
..79.2
... 50.0
.... 54.2
....100.
.... 5 8 3
.... 75.0
... 29.2
.... 87.5
Experimental Design: 8 treatments x 4 replications/treatmentx 6pots/replication x I cutting/pot. Cuttings of Daphne x
Burkwoodii 'Carol Mackie' were stuck October 1, 1984, following dipping in Wood's rooting compound, 1:10
dilution.
2
Plants were considered rooted when roots were visible in the drainholes of the 2.25" square x 3.25" deep pots.
3
One inch of Peat 50%, Perlite 50% medium containing 0.5 lbs N per cubic yard from Osmocote 18-6-12 was placed
in bottom of pots of this treatment.
4
GCC = Garden Care Compost
Being a hybrid between an evergreen and a deciduous plant, `Carol Mackie' varies in leaf
retention depending on the climate in which it is grown. At Aurora, Oregon, in U.S.D.A. Zone
7B in a cold winter, only the last leaves produced are retained; if the temperature does not fall
below 20°F, most leaves remain. In North Dakota (4) and Vermont (1) where `Carol Mackie'
will grow and bloom, it is a deciduous shrub.
I. Propagation Experiments
Effects of Propagation Media and Fertilization on Rooting:
Cuttings were stuck and rooted in 2 1/4" square x 3 1/4" deep pots. Rooting in pots does take
more space than rooting in beds or in flats but has advantages. First, losses of rooted `Carol
Mackie' cuttings were high when moved bare root. Second, cuttings tend to deteriorate if left
under a mist system too long; being able to remove individually-containerized cuttings as they
root (roots showing in the container's drain holes) is an advantage. This also makes space available sooner than waiting for all cuttings to be well-rooted.
In experiment 1 (Table 1), perlite and pumice were used alone or with 20% peat or compost.
Garden Care Compost (Portland sewage sludge composted with sawdust) was tested as an
alternative to peat. There are slight variations in mineral content and pH between batches of the
compost. An average mineral content of six batches of compost used in experiments is shown in
Table 4.
Rooting varied from 29% in medium #7 (80 pumice : 20 peat + Osmocote) to 100% in medium
#4 (80 perlite : 20 compost). Best total rooting occurred in treatments where rooting occurred
earliest: Medium #1 (100 % Perlite) had 79% rooting; medium #4 (Perlite 80, Compost 20) had
100% rooting; 75% rooting in medium # 6 (Pumice 80, Peat 20); and, 87.5% rooting in medium
#8 (Pumice 80, Compost 20). Fast rooting is important to reduce leaf loss during propagation.
Compost combined with either perlite or pumice gave greater rooting than did peat
combined with perlite or pumice. Garden Care Compost has also increased rooting of
Photinia, Rhododendron, and Thuja (3, 5, 6).
The effect of Osmocote 18-6-12 at 0.5 lbs N per cubic yard mixed in 50:50 peat:perlite in the
bottom inch of the pot with the balance being 20% peat with either perlite or pumice was
evaluated (Table 1, media #3, #7). Rooting and subsequent growth with Osmocote in the bottom
of the pot were no better or worse than the control treatments (Media #2, #6).
Perlite-peat and pumice-peat media amended with Osmocote fertilizer were inferior to perlitecompost and pumice-compost media.
Compost combined with either perlite or
pumice was clearly superior to either
material alone. The speed and
percentage rooting were better with
pumice (Table 2).
To determine whether the acidity and low fertility of the peat were responsible for the lower
percent rooting in the pumice-peat medium #6 (Table 1) compared with the pumice-compost
medium #8 (Table 1), the effects of adding lime and slow release fertilizer to a pumice-peat
medium were tested:
1) Table 3, medium #3 - 4 lbs limestone and 2 lbs dolomite per cubic yard were added;
2) Table 3, medium #4 - 4 lbs limestone, 2 lbs dolomite, 3 lbs Sierra 17-9-13, and 1.5 lbs
MicroMax per cubic yard were added. This amended medium is comparable in chemical
composition to the pumice - Garden Care Compost and pumice-ComPeat media (Table 3, media
#5, #6). ComPeat is a 50:50 mixture of Hypnum peat and spent mushroom compost from the
Bonaparte Peat Company. Chemical analyses of the Compost and ComPeat are presented in
Table 4. Sierra 17-9-13 was developed for use in small tubes and pots. The plastic coated prills
are much smaller than those of the regular Sierra fertilizer products.
Table 2. Effect of media on rooting of `Carol Mackie'
cuttings stuck on June 13, 19851
Number Rooted
Media
#1. Perlite 100%
#2. Perlite 80%, GCC3 20%
#3. Pumice 100%
#4. Pumice 80%, GCC3 20%
7/18
2
25
7/31 (total)
4 (9)
2 (41)
4 (17)
2 (45)
7/25
3
14
5
8
32
11
Percent
rooted
18.8
85.4
35.4
93.8
1
Experimental Design: I cutting/potx-6 pots/replication x 8 replications/treatment x 4 treatments. Cuttings of Daphne x
Burkwoodii:-'Carol Mackie' were stuck June 13, 1985, following dipping in Wood's rooting compound (1:10 dilution).
2 Plants were considered rooted when roots were visible in the drainholes of the 2.25' square x 3.25' deep pots.
3 GCC = Garden Care Compost.
Table 3. Effect of media on rooting of `Carol; Mackie'
cuttings stuck October 3, 19851.
Media
#1. Pumice 100%
#2. Pumice:Peat (80:20),
#3. Pumice:Peat (80:20)3
#4. Pumice:Peat 80.20)4
#5. Pumice:GCC (80: 20)
#6. Pumice:CP5 (80:20)
1
Number Rooted 2
11/20 12/19
1/6/86
4
-
3
7
5
9
3
7
7
8
5
4
13
9
13
Total
4/7/86 -
Percent
Rooted
..20
3
11
27
25
28
66.7
10.0
36.0
90.0
83.3
93.3
Experimental Design: 6 media treatments x 5 replications/treatment x 6 pots/replication x 1 cutting/pot. Cuttings of
Daphne x Burkwoodii `Carol Mackie' were stuck on October 3, 1985, following dipping in Wood's rooting compound
(1:10 dilution).
2
Plants were considered rooted when roots were visible in the drainholes of the 2.25” square x3.25" deep pots.
3
Peat fortified with Limestone 4 lbs and Dolomite 2 lbs/cubic yard.
4
Peat fortified with Limestone 4lbs, Dolomite 2 lbs, MicroMax 1.5 lbs and Sierra 17-9-13 3 lbs per cubic yard.
5
GCC = Garden Care Compost; CP = ComPeat.
Table 4. Mineral content
of the composts used in
Daphne x ‘Carol Mackie’
propagation and growing
trials
Garden
Care
Compost
% DRY WT
N 1.40
P 1.68
K 0.20
Ca 1.32
Mg 0.34
S 0.52
Fe 1.57
Al 1.56
ppm DRY WT
Mn 608
Cu 528
B 14
An 1454
Na 449
As 95
Cd 3.5
Ni 38
Pb 105
Com Peat
2.18
0.68
0.60
1.31
0.62
2.29
0.74
0.71
412
132
23
88
2293
67
0.4
9
96
The addition of limestone and dolomite to the pumice-peat
medium #3 (Table 3) did increase the percent rooting compared
to pumice-peat alone (medium #2), but it was still less than that in
pumice alone (medium #1). Addition of Sierra 17-9-13,
MicroMax, limestone and dolomite to the pumice-peat
(medium #4) increased rooting to levels comparable to those
of pumice-compost or pumice-ComPeat media.
Daphne X 'Carol Mackie' can be rooted in
satisfactory percentages using either 80%
perlite or pumice mixed with 20% Garden Care
Compost, ComPeat, or peat moss supplemented
with lime, slow release fertilizer and trace
elements
• Effect of Propagation Date on Rooting:
Effects of several propagation dates from May to October are
reported in Tables 1, 2, and 3. Brickell (2) reported that all clones
root readily from stem cuttings, particularly short soft cuttings
taken with a heel from June to August. Heel cuttings are time
consuming to take and require more care in sticking. In the current experiment, plain terminal
cuttings treated with Wood's Rooting Compound at a 1 in 10 dilution were stuck in different
rooting media.
Rooting was faster in late spring-early summer than in fall stuck cuttings, but final rooting
percentages were similar (Tables 1, 2, 3).
October propagation was slower than summer
propagation.
Softer cuttings were used in June 1985 (Table 2), and rooting was much faster: 7 weeks to final
evaluation in June compared to 11 weeks to the first evaluation and 24 weeks final evaluation for
the October 1984 trial (Table 1).
Table 5. Height and branch number of Daphne x burckwoodii
‘Carol Mackie’ following application of Atrinal to plants
grown in potting media containing two Osmocote formulations
Atrinal
Rates
Osmocote
Eormula
14-14-44
19-6-12
500 ppm 14-14-14
19-6-12
1000 ppm 14-14-14
19-6-12
2000 ppm 14-14-14
19-6-12
4000 ppm 14-14-14
19-6-12
6000 ppm 14-14-14
19-6-12
Check
L.S.D. 5%
1%
Height
(cms)
# of branches
Long Short
24.1
18.9
18.6
21.6
18.1
16.2
19.7
16.7
17.0
12.4
14.9
8.3
4.4
4.0
4.9
4.7
4.1
3.3
3.9
3.7
4.1
3.0
4.3
1.3
3.9
5.2
1.8
2.4
0.0
0.0
0.6
0.0
1.9
2.0
0.4
2.6
11.4
15.7
5.3
10.2
Table 6. Plant size and leaf retention ratings of Daphne x
burkwoodii `Carol Mackie' on December 22, 1987, as influenced
by a growing media x fertilizer trial started June 30, 1986.
FERTILIZER (Release Rate)
Bark 90% Sand 10%2
2 lbs Nitrogen per cubic yard:
Osmocote 17-7-10 (12-14 mo.)
Osmocote 18-6-12 (8-9 mo.)
Fast Start .
Osmocote 24-5-7 (14-16 mo.)
Osmocote 24-5-8 (12-14 mo.)
Height
(cms )
Width
(cms)
Leaf
Rating 1
40.5A
31.6BC
42.9A
31.5BC
3.4A
1.2C
26.1D
32.6B
24.0D
28.1C
3.0 AB
..1.6C
Garden Care Compost 3 50% Bark
40% Sand 10% 1lb Nitrogen/yd3
Osmocote 39-0-0 (8-9 mo.)
Osmocote 18-6-12 (8-9 mo.)
Fast Start
Osmocote 24-5-7 (14-16 mo.)
Osmocote 24-5-8 (12-14 mo.)
28.3CD
22.7D
1.4C
33.1B
33.2B
35.1B
32.6B
32.8B
35.0B
2.7AB
2.4B
..3.3AB
'Ratings: 1 = No leaves; 2 = Few terminals have leaves; 3 = Half of terminals have leaves; and, 4 = All terminals have leaves.
2PIus Dolomite, Gypsum, Limestone, and MicroMax all at 1.5lhslcu yd.
3Portland sewage sludge composted with sawdust.
Daphne X burkwoodii can be rooted from June to
October. Faster rooting occurs in June than in
October, but the final rooting percentages are
similar.
II. Effects of Atrinal and Fertilizer Formulation on Branching
Although `Carol Mackie' does branch well and forms a dense plant with time, first year
branching can be sparse. Dikegulac-sodium (Atrinal, Attramec) applied as a foliage spray to
actively growing plants will induce branching in many species. Cuttings were stuck May 20th
and potted into 4" pots on June 28th. The growing medium was bark (90%) and sand (10%)
amended with 3-4 month release Osmocote 19-6-12 or 14-14-14 plus lime and trace elements to
supply 2 lbs nitrogen per cubic yard of media. The pots were transferred to a capillary irrigation
bed on July 8th; some losses and injury occurred shortly after transfer due to excessive salts in
the potting media. Seven healthy plants from each fertilizer treatment were treated; five rates of
Atrinal (500, 1000, 2000,4000, and 6000 ppm) were applied on August 9, 1985.
Plant height and number of long branches (over 6 cm) and short branches (less than 6 cm) were
measured on April 7, 1986 (Table 5). Plants with 14-14-14 in the potting media were taller than
those with 19-6-12, with the exception of plants treated with 500 ppm Atrinal. Fertilizer and
Atrinal treatments did not significantly affect the number of long branches. Most of the long
branches were initiated before application of the fertilizer and Atrinal treatments.
The number of short branches was
increased by 2000 ppm or higher
amounts of Atrinal. However, some
plants looked like "Witches Brooms."
III. Growing Trial
Since Garden Care Compost increased rooting, the next trial was to determine whether it would
be beneficial in the growing media.
Two media were used (Table 6):
1) 90% bark and 10% sand with 2 lbs nitrogen from slow release fertilizers per cubic yard, and
2) 50% Garden Care Compost, 40% bark, and 10% sand with 1 lb of nitrogen per cubic yard.
The bark media was also supplemented with dolomite, gypsum, limestone and MicroMax at 1.5
lbs per cubic yard.
Three formulations from Sierra Chemical Company were used with both media:
1) 18-6-12 (8-9 mo release) Fast Start
2) 24-5-7 (14-16 mo) and
3) 24-5-8 (12-14 mo)
Two other Sierra formulations were used:
4) 39-0-0 (8-9 mo) was used with the compost medium only
5) 17-7-10 (12-14 mo) was used with the bark medium only.
`Carol Mackie' liners were potted into 1 gallon mesh bottom pots June 30, 1986, and were grown
on a capillary sand bed until April 15, 1987. Although the plants were primarily watered from
below, during July and August it was necessary to overhead water once a week to flush out the
excess salts. The overhead watering was decreased in September to once every two weeks and to
once a month during the winter when the capillary system was off. The bed was in a winter
protection house which was covered with white polyethylene from November 17, 1986 to April
15, 1987.
When the pots were lifted in the spring to increase spacing, many had extended root systems into
the sand bed. These roots were cut off, and the plants were moved to an overhead irrigated
gravel-surfaced area; no further roots grew out of the bottom of the pots.
With composted sewage sludge media, less slow
release fertilizer is required.
All pots were topdressed with 1 teaspoon of Nutricote 16-10-10 during June 1987. This amount
of Nutricote proved to be inadequate: By the end of the growing season, plants in some
treatments had lost most of their leaves. This did permit an assessment of the nutrient supplying
potential of the fertilizer-media combinations.
Measurements of height, width and a leaf retention rating are shown in Table 6. With the barksand medium, best plant growth occurred with Osmocote 17-7-10 at 2 lbs N per cubic yard.
17-7-10 was not used with the 50% compost media. Growth and leaf retention were similar or
better in compost media for the 3 comparable fertilizer products.
Literature Cited
1. Anonymous. 1980. Plants worth growing. The Green Mountain Grower No. 96, page 3.
2. Brickell, C.D. and B. Mathew. 1976. Daphne-The genus in the wild and in cultivation. pp. 1194. The Alpine Garden Society. U.K.
3. Hemphill, D.D. Jr., R.L. Ticknor, and DJ. Flower. 1994. Growth response of annual
transplants and physical and chemical properties of growing media as influenced by
composted sewage sludge amended with organic and inorganic materials. J. Envir. Hort.
2(4):112-116.
4. Herman, Dale E. 1985. Shrubs for Northern Plans landscapes. Amer. Nurs. 161(2)62-64, 6669.
5. Ticknor, RL., D.D. Hemphill, Jr. and DJ. Flower. 1985. Composted sewage sludge-a media
component for rhododendron production. Jour. Amer. Rhodo. Soc. 39(2):107-110.
6. Ticknor, R.L., D.D. Hemphill, Jr. and DJ. Flower. 1985. Growth response of Photinia and
Thuja and nutrient concentration in tissues and potting medium as influenced by composted
sewage sludge, peat, bark, and sawdust in potting media. Jour. Envir. Hort. 3(4):176-180.
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